Method and system for controlling a portable power system having a single battery bank

Abstract

A method for controlling a portable power system, comprising: using a processor, selecting an engine efficiency range for an engine of a generator set of the portable power system, the engine efficiency range corresponding to a power output range of the generator set and to a power demand range of a load coupled to the portable power system; while a power demand of the load is less than a power output of the generator set, storing excess energy from the generator set in a battery bank of the portable power system; while the power demand of the load is greater than the power output of the generator set, providing additional power to the load from the battery bank; when a first predetermined depth of discharge threshold is reached by the battery bank, increasing the power output of the generator set to allow the battery bank to recharge; and, when a predetermined state of charge threshold is reached by the battery bank, ceasing the power output of the generator set and providing power to the load from the battery bank until a second predetermined depth of discharge threshold is reached by the battery bank.

What is claimed is: 
     
       1. A method for controlling a portable power system, comprising:
 using a processor, selecting an engine efficiency range for an engine of a generator set of the portable power system, the engine efficiency range corresponding to a power output range of the generator set and to a power demand range of a load coupled to the portable power system; 
 while a power demand of the load is less than a power output of the generator set, storing excess energy from the generator set in a battery bank of the portable power system; 
 while the power demand of the load is greater than the power output of the generator set, providing additional power to the load from the battery bank; 
 when a first predetermined depth of discharge threshold is reached by the battery bank, increasing the power output of the generator set to allow the battery bank to recharge; and, 
 when a predetermined state of charge threshold is reached by the battery bank, ceasing the power output of the generator set and providing power to the load from the battery bank until a second predetermined depth of discharge threshold is reached by the battery bank. 
 
     
     
       2. The method of  claim 1  wherein the first predetermined depth of discharge threshold is 50% or approximately 50%, wherein the second predetermined depth of discharge threshold is 50% or approximately 50%, and wherein the predetermined state of charge threshold is 100% or approximately 100%. 
     
     
       3. The method of  claim 1 , further comprising equalizing a depth of discharge and a state of charge of the battery bank manually or automatically. 
     
     
       4. The method of  claim 1  wherein the battery bank contains one or more lithium-ion batteries. 
     
     
       5. The method of  claim 1  wherein the engine is one of a liquid natural gas engine and a diesel engine. 
     
     
       6. The method of  claim 1 , further comprising, when the power demand of the load is less than the power output of the generator set, providing power to the load from the generator set in addition to storing the excess energy from the generator set in the battery bank of the portable power system. 
     
     
       7. The method of  claim 1 , further comprising, when the power demand of the load is greater than the power output of the generator set, providing power to the load from the generator set in addition to providing the additional power to the load from the battery bank of the portable power system. 
     
     
       8. The method of  claim 1  wherein the portable power system includes another generator set having another engine. 
     
     
       9. The method of  claim 1 , further comprising selecting a set of predetermined operating states for the portable power system using the engine efficiency range. 
     
     
       10. The method of  claim 9 , further comprising controlling the generator set and the battery bank in accordance with the set of predetermined operating states. 
     
     
       11. A control system for controlling a portable power system, comprising:
 a processor coupled to memory, a generator set, and a battery bank; and, 
 at least one of hardware and software modules within the memory and controlled or executed by the processor, the modules including:
 a module for selecting an engine efficiency range for an engine of the generator set of the portable power system, the engine efficiency range corresponding to a power output range of the generator set and to a power demand range of a load coupled to the portable power system; 
 a module for, while a power demand of the load is less than a power output of the generator set, storing excess energy from the generator set in the battery bank of the portable power system; 
 a module for, while the power demand of the load is greater than the power output of the generator set, providing additional power to the load from the battery bank; 
 a module for, when a first predetermined depth of discharge threshold is reached by the battery bank, increasing the power output of the generator set to allow the battery bank to recharge; and, 
 a module for, when a predetermined state of charge threshold is reached by the battery bank, ceasing the power output of the generator set and providing power to the load from the battery bank until a second predetermined depth of discharge threshold is reached by the battery bank. 
 
 
     
     
       12. The control system of  claim 11  wherein the first predetermined depth of discharge threshold is 50% or approximately 50%, wherein the second predetermined depth of discharge threshold is 50% or approximately 50%, and wherein the predetermined state of charge threshold is 100% or approximately 100%. 
     
     
       13. The control system of  claim 11 , further comprising a module for equalizing a depth of discharge and a state of charge of the battery bank manually or automatically. 
     
     
       14. The control system of  claim 11  wherein the battery bank contains one or more lithium-ion batteries. 
     
     
       15. The control system of  claim 11  wherein the engine is one of a liquid natural gas engine and a diesel engine. 
     
     
       16. The control system of  claim 11 , further comprising, a module for, when the power demand of the load is less than the power output of the generator set, providing power to the load from the generator set in addition to storing the excess energy from the generator set in the battery bank of the portable power system. 
     
     
       17. The control system of  claim 11 , further comprising, a module for, when the power demand of the load is greater than the power output of the generator set, providing power to the load from the generator set in addition to providing the additional power to the load from the battery bank of the portable power system. 
     
     
       18. The control system of  claim 11  wherein the portable power system includes another generator set having another engine. 
     
     
       19. The control system of  claim 11 , further comprising a module for selecting a set of predetermined operating states for the portable power system using the engine efficiency range. 
     
     
       20. The control system of  claim 19 , further comprising a module for controlling the generator set and the battery bank in accordance with the set of predetermined operating states.